The invention relates to a system for controlling an internal combustion engine, in particular, self-igniting internal combustion engine pursuant to the introductory part of the independent claim.
Such a system is disclosed by the German Published Patent Application 33 43 481. It describes a method and device for controlling a self-igniting internal combustion engine comprising a correcting means, which compensates for the correlation that changes over time between the quantity of fuel which is actually injected and the positional signal from the final quantity-determining controlling element.
This method provides for a signal-detecting sensor, which indicates the quantity of fuel actually injected. In the method described, this corresponds to a sensor for detecting the position of the control rod. Such a sensor supplies only a very inaccurate signal with respect to the injected fuel quantity For this reason, it is also tested in an overrun operation, to determine the point (triggering signal) at which no more fuel injection takes place. A needle-motion sensor is used to test for such injections.
The German Published Patent Application 30 11 595 discloses another method and another device for correcting manifestations of drift. With this method, the setpoint value for the quantity of fuel to be injected is corrected so as to allow the correlation between the positional signal of the final quantity-determining controlling element and the fuel quantity actually injected to conform. This document does not reveal how these correction values are determined.
These systems require the sensors to operate for a very long period of time and the sensors only supply very inaccurate values.
The object of the invention is to make it possible to use a simple and precise open-loop control for an internal combustion engine in a system for controlling that engine. More particularly, it is the aim of the invention to make available a very precise load signal for controlling additional variables, such as the exhaust-gas recirculation rate and/or the start of injection.
The system according to the invention results in a significantly more precise open-loop control for internal combustion engines. In particular, the exhaustgas emissions are able to be considerably reduced.
Advantageous and useful refinements and further developments of the invention are characterized in the dependent claims.